Commitments and Contingencies - Narrative (Details) $ in Millions	1 Months Ended		12 Months Ended
	Jan. 31, 2026 USD ($) plaintiff	Jan. 31, 2025 plaintiff	Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Jan. 31, 2023 USD ($)
Commitments and Contingencies
Environmental loss contingency accrual			$ 3	$ 3
Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration]			Accrued Liabilities	Accrued Liabilities
Minimum Carbon Dioxide Supply						$ 15
Maximum fee payable						$ 45
Number of Plaintiffs | plaintiff		3
Energy
Commitments and Contingencies
Expense (benefit)			$ 94	$ 46	$ 114
RFS position			72	$ 323
Insurance policies coverage limits			$ 50
Icahn Enterprises Holdings
Commitments and Contingencies
Affiliate ownership interest			98.01%
Mr. Icahn and affiliates | Minimum
Commitments and Contingencies
Affiliate ownership interest			80.00%
Icahn Enterprises G.P. | Mr. Icahn and affiliates
Commitments and Contingencies
Affiliate ownership in parent company general partner			100.00%
Icahn Enterprises Holdings | Mr. Icahn and affiliates
Commitments and Contingencies
Affiliate ownership interest			86.00%
ACF
Commitments and Contingencies
Funded status of related party pension plan			$ 19
ACF | Icahn Enterprises Holdings | Minimum
Commitments and Contingencies
Ownership percentage by principal owner			80.00%
Starfire Holding Corporation
Commitments and Contingencies
Ownership percentage by principal owner			99.60%
Pension funding indemnity agreement with subsidiary			$ 250
Subsequent event
Commitments and Contingencies
Number of Plaintiffs | plaintiff	3
Subsequent event | Minimum
Commitments and Contingencies
Amount of quantifying alleged damages	$ 5